docs: def send_request_message(self, request_id, meta, body, _=None):
          """
          Receives a request from the client and handles and dispatches in in-thread. `message_expiry_in_seconds` is not
          supported. Messages do not expire, as the server handles the request immediately in the same thread before
          this method returns. This method blocks until the server has completed handling the request.
          """
          self._current_request = (request_id, meta, body)
          try:
              self.server.handle_next_request()
          finally:
              self._current_request = None